1. Field of the Invention
The present invention relates to a heat sink assembly, and more specifically to a heat sink assembly having a fixing device for readily securing a fan to a heat sink and pressing the heat sink onto a CPU.
2. Related Art
A conventional heat sink assembly for a CPU includes separate parts such as a heat sink, a heat sink clip, a fixing device and a fan. In assembly, the fan is mounted to the heat sink by the fixing device. Then the combined heat sink and fan is secured to a top surface of the CPU by means of the clip engaging with catches on a CPU socket or holes in a printed circuit board. The clip and the fixing device are separate parts which must be installed or removed separately. This is unduly time-consuming and costly.
Furthermore, the fan is frequently secured to the heat sink using a plurality of screws engaging with fins of the heat sink. The screws frequently distort or even damage the fins. Moreover, fins of contemporary heat sinks are often particularly thin, to maximize dissipation of great amounts of heat generated by contemporary CPUs. Thus it is becoming increasingly difficult to adequately secure a fan to a heat sink using screws.
An improved means of securing a fan to a heat sink which overcomes the above problems is desired.
Accordingly, an object of the present invention is to provide a heat sink assembly having a fixing device which readily attaches a fan to a heat sink and presses the heat sink onto a CPU.
Another object of the present invention is to provide a heat sink assembly having a fixing device which is simply in structure and cost-efficient.
To achieve the above-mentioned objects, a heat sink assembly comprises a heat sink, a fan, and a fixing device. The fixing device comprises an engaging portion for pressing the heat sink onto a CPU, and a fixing portion for securing the fan to the heat sink. The engaging portion has a pressing section received in a slot of the heat sink, two spring sections at each side of the pressing section also received in the slot, and two legs depending from opposite ends of the spring sections. An aperture is defined in each leg, for engaging with a corresponding catch of a socket. The fixing portion has a frame, and four clamps in the vicinity of four corners of the frame. Each clamp has a slit, and a pair of barbs at a distal end of the clamp. A pair of integrating flanges depends from opposite sides of the frame, each integrating flange integrally connecting with a corresponding leg of the engaging portion.